A quick and easy guide to naming and writing them Multivalent ions A quick and easy guide to naming and writing them

What are multivalent ions? Multivalent: multi (more than one) + valent (number of valence electrons) AKA. Multiple Charges Atomic Number (# p+) Ion Charge Symbol Multivalent = 4+ or 3+ Name Atomic Mass

MultiValent Ions Transition Metals More common ones Iron (Fe) 3+ or 2+ Lead (Pb) 2+ or 4+ Nickel (Ni) 2+ or 3+ Copper (Cu) 2+ or1+ Gold (Au) 3+ or 1+

Distinguishing charges Numerals are used when indicating an ion’s charge. Charge Roman Numeral +1 I +2 II +3 III +4 IV +5 V +6 VI +7 VII

Examples of multivalent charges Fe 3+  iron (III) Cu 1+  copper (I)

Naming multivalent ions Example: Au3N Identify the metal and list the possible charges Au = 3+ or 1+ Identify the non-metal and it’s charge N = 3- Notice how many ions of each you have 3 Au ions AND 1 N ion Figure out what charge needs to be used so that the positive and negative charges balance out 3 Au ions = +1 +1 +1 = +3 1 N ion = -3 Determine which roman numeral to use for the metal charge Au (I) Write the compound name (non-metal suffix is “ide”) Gold (I) Nitride

Practice Naming Example: PdS2 Identify the metal and list the possible charges Pd = 2+ or 4+ Identify the non-metal and it’s charge S = 2- Notice how many ions of each you have 1 Pd ion AND 2 S ions Figure out what charge needs to be used so that the positive and negative charges balance out 1 Pd ion = +4 = +4 2 S ions = -2 -2 = -4 Determine which roman numeral to use for the metal charge Pd (IV) Write the compound name (non-metal suffix is “ide”) Palladium (IV) sulphide

Writing formulas Example: manganese (IV) sulfide Figure out what these two ions are and write down their charges Manganese (IV) = Mn+4 S = S-2 Determine how many of each ion you need to balance out the charges Mn+4 = +4 S-2 = - 2 You will need another ion of S to balance Note the ratio of positive ions to negative ions 1 Mn 2 S Write the formula, indicating the number of each ion in a subscript right after if MnS2

Practice writing the formula Example: colbalt (III) oxide Figure out what these two ions are and write down their charges Colbalt (III) = Co+3 O = O-2 Determine how many of each ion you need to balance out the charges Co+3 = +3 +3 = +6 O-2 = - 2 -2 -2 = -6 Note the ratio of positive ions to negative ions 2 Co 3 O Write the formula, indicating the number of each ion in a subscript right after if Co2O3